Summary Chapter One 1. Scientific Method (know definitions). 2. Quantitative versus Qualitative measurements. 3. Accuracy versus Precision.

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1 Summary Chapter One 1. Scientific Method (know definitions). 2. Quantitative versus Qualitative measurements. 3. Accuracy versus Precision. 4. Systematic versus Random errors. 5. Significant Figures. 6. Dimensional Analysis. 7. Density. 8. Classification of Matter.

2 Density Solid sodium has a density of g/cm 3. What is the average volume occupied by one atom of sodium in units of cm 3?

3 Significant Figures (26.3)(0.0010) (a)2000 (b)1700 (c)1710 (d)1708 (e)1708.6

4 Summary Chapter Two 1. There are lots of names and dates in this chapter, what was covered in class is what I find important. 2. Lavoisier law of conservation of mass. 3. Proust law of definite proportion. 4. Dalton Law of multiple proportions and Dalton s atomic theory. 5. J.J. Thomson cathode ray experiment and plum pudding model. 6. Rutherford alpha-particle bombardment experiment. 7. Nuclear Atom. 8. Isotopes 9. Periodic Table (groups, periods, metals, nonmetals) 10. Memorize names of elements 1-36, Tables Simple molecule formation. 12. Nomenclature of ionic and covalent compounds.

5 Isotopes Identify the isotope which has a mass number of 185 and whose +3 ion has 72 electrons: a) b) Ir Ir c) Re d) e) Tm Tm

6 Conceptual Question Which of the following statements is FALSE? a) An atom is mostly empty space. b) Glucose (C 6 H 12 O 6 ) is an example of a covalent compd. c) CaF 2 contains an alkali metal and a halogen. d) When a metal forms a compound with a nonmetal, an ionic compound generally results. e) Metals generally form stable cations in ionic compounds.

7 Summary Chapter 3 1. Atomic mass, relative atomic mass. 2. The mole. 3. Molar mass. 4. Mass percent. 5. Empirical versus molecular formula. 6. Combustion analysis and mass % problems. 7. Stoichiometry and Limiting Reactant problems.

8 Mole How many sulfur atoms are present in 0.25 mol of aluminum sulfide?

9 Mass % A binary compound between an unknown element E and hydrogen contains % E and 8.73% H by mass. If the formula is E 3 H 8, what is the identity of E?

10 Combustion Analysis A sample of LSD (D-lysergic acid diethylamide, C 24 H 30 N 3 O) is added to some table salt (sodium chloride) to form a mixture. Given that a 1.00 g sample of the mixture undergoes combustion to produce 1.20 g of carbon dioxide, what is the mass % of LSD in the mixture?

11 Stoichiometry For the next two questions, consider the following reaction between two hypothetical elements A and B: 2A (g) + 3B 3 (g) A 2 B 9 (g) Molar masses: A: 40.0 g/mol; A 2 B 9 : 125 g/mol Initially a reaction vessel contains 11.0 moles of A and 12.0 moles of B 3. Assuming the above reaction goes to completion answer the following questions: 1. If 4.0 moles of A 2 B 9 are formed in the reaction, how many moles of A are left unreacted? 2. What is the total mass of B 3 consumed in the reaction?

12 Summary Chapter 4 1. Water as a solvent. 2. Solubility Rules. 3. Identifying strong, weak and nonelectrolytes. 4. Concentration. 5. Dilution. 6. Precipitation reactions. 7. Solution stoichiometry. 8. Acid/Base Definitions. 9. Titration definitions. 10. Titration problems.

13 Electrolytes How many of the following substances are strong electrolytes? Sr(OH) 2, AgCl, Na 2 S, HNO 3, CH 3 COOH insoluble insoluble Exceptions: Salts of alkali metals and ammonium cations.

14 Dilution A solution is made by mixing 50.0 ml of 6.00 M HCl with ml of M HCl. This mixture is diluted by adding water until the final solution volume is ml. What is the molarity of the final solution of HCl?

15 Precipitation Reactions Consider the following information for the next three questions ml of M lead (II) nitrate is added to 75.0 ml of M ammonium phosphate and a precipitate forms. 1. What is the net ionic equation. 2. How many moles of precipitate are formed assuming 100% yield? 3. Calculate the molarity of ammonium ions after the precipitation is complete.

16 Titration What volume of M Ba(OH) 2 is required to react completely with ml of M H 3 PO 4? Phosphoric acid contains three acidic hydrogens.

17 Summary Chapter 6 1. When H > 0 the reaction needs heat to proceed to products (heat is a reactant). This is called an endothermic reaction. 2. When H < 0 the reaction releases when reactants are converted to products (heat is a product). This is called an exothermic reaction. 3. Stoichiometry implied from reaction. 4 Fe (s) + 3 O 2 (g) 2 Fe 2 O 3 (s) H = kj

18 Summary Chapter 5 1. Properties of gases. 2. Methods of measuring pressure of gases. 3. Boyle s Law, Charles Law, Avogadro s Law. 4. Ideal gas law. 5. Dalton s law of partial pressures.

19 Properties of Gases A bag of potato chips is packed and sealed in L.A. California, and later shipped to Deming, New Mexico. In Deming it is noticed that the volume of the bag of potato chips has increased. Which of the following external conditions (a-c) could cause the volume of the bag of potato chips to increase in Deming as compared to L.A.? (Assume no gas molecules can enter or leave the bag of potato chips and assume no chemical reaction occurs inside the bag). a)the temperature outside the bag decreased. b)the pressure outside the bag decreased. c)the moles of air molecules outside the bag increased. d)none of the above.

20 Two Condition Problem An ideal gas in a flexible container occupies a volume of 10.0 L at 38ºC and 0.20 atm. If the gas sample is cooled to 7ºC and the volume is decreased to 3.60 L, what is the new pressure of the gas sample?

21 Ideal Gas The gases N 2 and H 2 in a closed container fitted with a movable piston (the piston allows the volume of the container to change in order to keep the pressure constant). Stoichiometric amounts of the gases are chosen so that neither is limiting (after the reaction below goes to completion, no N 2 or H 2 are present). If the original volume of the container is 8.0 L, what will be the volume of the container after the following unbalanced reaction goes to completion? Assume P and T are constant. N 2 (g) + H 2 (g) NH 3 (g)

1. My answers for this Chemistry 102 exam should be graded with the answer sheet associated with: a) Form A b) Form B c) Form C d) Form D e) Form E

Hour Exam I Page 1 1. My answers for this Chemistry 102 exam should be graded with the answer sheet associated with: a) Form A b) Form B c) Form C d) Form D e) Form E 2. Consider the measurements 9.74